Re: [linux-lvm] Mirroring my install. Lots of problems !

[Luca Berra <bluca comedia it>]

On Mon, Jan 15, 2007 at 10:42:26AM +0100, Georges Giralt wrote:
...
> The conversion was a failure, because the tools asked for a THIRD disk in order
> to mirror the VG. Funny. I thought GNU/Linux was clever, I was wrong. How come
> HP-UX or Aix can do LVM mirror on 2 disks and not Linux ? (the corelog option
> is also an issue, as reconstruction will take place at every reboot which occur
> often as this is a home box, not a server)
i am still waiting for the lvm mirror interface to settle before trying
to use it, so i cannot comment...

> So I decided to try a more complex approach : Create a mirror using the mdtools
> (mdadm) and turn this into a VG. My plan was as follow :
> 1) create a critical mirror using mdadm with only one copy active on hdb2 repeat
> with hdb3.
> 2) pvcreate md0 and md1
> 3) add md0 to vg0 and md1 to vg-ext
> 4) pvmove all vg0 lv to md0 and all vg-ext lv to md1.
> 5) vgreduce vg0 to remove hda2 and vg-ext to remove hda3
> 6) add hda2 to md0 and hda3 to md1 and force re-sync
> 7) have a beer, and enjoy.
this is the best part of your plan :)
> Again, a disaster. I CAN'T add an md to a vg and have the vg work. I've tried to
> do it using plain md0 to pvcreate, partitionning md0 to create md0p1 and
> pvcreate this (it's impossible, as there is no /dev/md0p1 device...)
can you please be more verbose as to why you can't add an md to a vg
eg showing logs and output of lvm commands with verbose options.
i usually pvcreate md devices without any problem.

regards,
L.

--
Luca Berra -- bluca comedia it
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